(1) Field of the Invention
The present invention relates to a cooling system used on turbine engine components, such as turbine blades, which allows for tip blowing on the pressure side of the tip.
(2) Prior Art
The overall cooling effectiveness is a measure used to determine the cooling characteristics of a particular design. The ideal non-achievable goal is unity, which implies that the metal temperature is the same as the coolant temperature inside an airfoil. The opposite can also occur where the cooling effectiveness is zero implying that the metal temperature is the same as the gas temperature. When that happens, the material will certainly melt and burn away. In general, existing cooling technology for turbine engine components, such as turbine blades, allows the cooling effectiveness to be between 0.5 and 0.6. More advanced technology, such as supercooling, should be between 0.6 and 0.7. Microcircuit cooling as the most advanced cooling technology in existence today can be made to produce cooling effectiveness higher than 0.7.
One problem which occurs is that as Rotor Inlet Temperature RIT increases, blade tip erosion may surface as a weak point in the design of a high pressure turbine blade.